Regarding this new question in this old thread:
https://www.corvetteforum.com/forums...post1607927149
I wrote a long answer only to find that the thread was locked while I was writing.

Anyway, I post this as a new thread instead.
I bought my 1984 Corvette in 1998 and this is what is looked like in 2001 when I thought that I was more or less finished with the modifications. I was wrong but that is another story.

I bought a Vortech V1 superharger as a used kit for a Ford Bronco.
To make some room for it I used the A/C fracket for TPI and fabricated som brackets to first move the alternator closer to the midde where the AIR pump used to be.



Then made some more brackets to mount the supercharger where the alternator and power steering reservoar used to be.




I made a box to replace the stock air cleaner assembly.



The stock ECU uses a 1 bar MAP sensor and it is blind to boost. To get extra fuel I installed an adjustable progressive 2:1 fuel pressure regulator on the return line after the stock regulatior located in the rear TBI ( right on this picture )
I also replaced the stock fuel pump with a "LT1" fuel pump with higher pressure rating.



Fuel pressure is regulated by restricting the return flow. With two regulators in series the one that commands the highest pressure wins.
By adjusting the spring preload I could keep the stock fuel pressure up to atmospheric, and raise fuel pressure with boost.
This is all I did for extra fuel. This solution works better when you start with a low fuel pressure, like the CFI.
To get 40% more fuel you need to double fuel pressure.
Raising fuel pressure from 13 to 26 psi on a Cross-Fire is easier than 45 to 90 psi pn a TPI.


And this is the "finished" look and air conditioning was still working,





I used a "street dyno" software to compare power with and without supercharger,
Using a laptop I recorded the VSS signal on the microphone input.
With the "street dyno" software this could be converted to a speed signal and from this acceleration could be calculated.
Knowing the vehicle weight both power and tourqe can be calculated.
These numbers might not be absolutley correct, but the comparison is valid.

I measured a 60% peak power increase.
At 5000 rpm I measured almost double the power.
The power band moved up and this is normal with centrifugal superchargers.



The original question was about turbo, but boost is boost.

 

Hey Joby! You still at it with your 84? Just wondering. If you remember GeekyBill from the CF Vault days, I talked with him the other day.

 

Another '84 owner here. I put a turbo on mine in that same time frame. I had to lose the non-working A/C to put the turbo outside of cylinders 4&6, but on several of the tuning points or details I ended up going with a similar solution as you did.

Boost is a ton of fun.

I'd like to hear additional details if you\re inclined to discuss them.

 

Yes, I drove it to work today. I have some ongoing projects, but a lot of other stuff takes most of my time.
Sure, I remember GeekyBill


Yes, those pictures were from over 20 years ago.

The next iteration was an Offenhauser Cross-Ram that is similar to the Cross-Fire but full size ports.
I made a custom lid and turend one TB backwards to get better spacing on this bigger intake.

With this bigger intake there were no room for the alternator in front of it, so the A/C compressor had to go.

I had i running but with new AFR aluninum heads, bigger cam and this intake the stock ECU was way off.
A modern ECU would have made a huge differance when tining.

 

The I bored and sleved the TB's to 2" and installed the largest available injectors from 454 CUI TBI.







Then to get some tunability I modifies a 7747 ECM with an adapter board developed by "GeekyBill" on the old Cross-Fire Forum.

Most of the tuning tables where known for the 7747 but I installed a 2-bar map sensor so everything had to be scaled and extended to work with boost.

Every tuning iteration had to me programmed to chips and then installed in the ECU. It was very time consuming for slow progress.








I never finished tuning this setup for boost, because the th700r4 died on me more or less directly.

 

WOW! that's a blast from the past seeing a 7747 and a rather old HAM Board. The new HAMs are much different, Rev: D Are you still running that ECM?

I also did a custom bore on some TBs for my motor lately, 56mm, haven't installed them yet, but this winter I will and tweak the tune. My goal is 11.99 or better NA CFI. I'm almost there.

 

Hey JoBy, good to see you on again.
That looks like the Offenhauser 5893 intake base. Did you have any trouble with what looks like it's taller than stock intake height matching up with the hood ducts?

 

That was one of the first boards made. No, I did not run that 7747 for long. Transmission broke down and I decided to get something stronger instead of rebuilding again. I also built a new garage so the Corvette was parked for a couple of years.

 

No, everything still fit under the hood. Not sure how the ducts lined up, but could not have been too far off. Biggest poblem was wiper motor. I had to modify another wiper motor without park funktion and it was still very tight.